How to Modify Normal Orientation from e57 file

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smoluck
Posts: 15
Joined: Mon Dec 02, 2019 2:15 am

How to Modify Normal Orientation from e57 file

Post by smoluck »

Hi, everyone.

Here is the problem:

I've took multiple Lidar Leica Scan Data that i've imported from Cyclone 2021 to E57.
(Point Position / RGB / Normals)


Once in Metashape the XYZ Data is good, but the Normals
are not converted according to the difference between the 2 software. they're using different Coordinate convention.


Coordinate system between Cyclone and Cloud Compare (or Metashape) is mismatching.
(Rotation of 90 degrees on Z Axis should be applied).


You can notice that the deck ground, Z up normals are matching correctly. So in the Mesh Build the result is good because the normal Data on Z is not not affected by any change.
However the element that are not looking up top are not matching (walls, side panels).


So the question is how we can modify the Surface Normals Data in Cloud Compare in order to match the given Coordinate Axis setup ?

Here is the video that describe the problem i'm facing.
https://www.youtube.com/watch?v=KX7jDaoBeWY
daniel
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Joined: Wed Oct 13, 2010 7:34 am
Location: Grenoble, France
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Re: How to Modify Normal Orientation from e57 file

Post by daniel »

Are you sure about this 90 degrees rotation? Have you asked Agisoft about that? (it would be surprising if it's not a bug, and such a bug would be... well, very bad ;).

In CloudCompare, there's no way to rotate the normals but not the points (everything rotates together). The only option you would have is to load the cloud (with normals) as an ASCII file, and then choose a different order (X / Y / Z) for the points and for the normals. But that won't result in a clean rotation (as normally one of the dimensions should be inverted as well...).
Daniel, CloudCompare admin
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